(a) Field
Embodiments of the present invention relate a switch controller and a converter.
(b) Description of the Related Art
An input voltage of a converter is converted into an output voltage through a power conversion means such as a transformer. A high-side switch and a low-side switch are connected to a primary side of the transformer, thereby controlling power supplied to the primary side. Thus, the power transmitted to a secondary side of the transformer is controlled and the output voltage is controlled. That is, the output voltage of the converter is controlled by each switching operation of the high-side switch and the low-side switch.
A current flowing to the primary side is generated according to resonance between an inductor of the transformer and a blocking capacitor blocking a DC component into the primary side of the transformer. The high-side switch and the low-side switch process zero voltage switching or zero current switching according to a phase of the current of the primary side.
When each switching operation of the high-side switch and the low-side switch fails the zero voltage switching and is zero current switching, hard switching occurs. Also, a shoot-through current may be generated by a reverse recovery. The high-side switch and the low-side switch are turned on by the reverse recovery such that the shoot-through current is a current flowing through two switches.
When hard switching and the shoot-through current are generated by the failure of the zero voltage switching, a quick current increase and noise are generated. The quick current increase causes damage to elements of the converter such as a metal-oxide semiconductor field-effect transistor (MOSFET).
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.